In metering electric power as used, for example, in a residence, a meter box is provided with a set (usually four) of jaw contacts mounted onto the back wall of the box. The electric meter is provided with blade contacts on the rear, which plug into the jaw contacts when the meter is assembled. The meter is mounted in and retained in place by the box cover, which may be of the ringless type, in which the meter aperture in the cover is sized so that the periphery of the cover around the aperture bears against the meter flange, or of the ring type, in which the portion of the box cover around the aperture is formed into an outwardly curled lip, and a clamping ring is used to clamp the meter flange to the lip.
In either type of box, the jaw contacts often become corroded, lose their spring action so that a good contact is not made with the meter contact blades, or are damaged by vandals or by persons attempting to obtain power without it being recorded by the meter. In such a case it has heretofore often been necessary remove and replace the entire meter box. In many installations this is a difficult and time consuming job, since it requires that the power lines be removed from the old box and inserted into the new box. This can be particularly difficult in situations where a number of meter boxes are mounted closely together, such as in an apartment building.